Anti-aircraft defense systems



Aug. 1, 1961 Filed Jan. 8, 1942 M. l. HULL ANTI-AIRCRAFT DEFENSE SYSTEMS 9 Sheets-Sheet 5 22 F IG. 9. 2 4

INVENTOR.

MAURY I. HULL F ATTYS.

Aug. 1, 1961 M. l. HULL 2,994,270

ANTI-AIRCRAFT DEFENSE SYSTEMS Filed Jan. 8. 1942 9 Sheets-Sheet 4 F 6.10. FEGJI IN V EN TOR.

AUY E. ULL

TQM/Z Aug. 1, 1961 M. l HULL 2,994,270

ANTI-AIRCRAFT DEFENSE SYSTEMS Filed Jan. 8, 1942 9 Sheets-Sheet 5 INVENTOR. m MAURY I. HULL Aug. 1, 1961 Filed Jan. 8, 1942 M. 1. HULL 2,994,270

ANTI-AIRCRAFT DEFENSE SYSTEMS 9 Sheets-Sheet 6 FIG.18.Y

INVENTOR.

AAURY I. HULL 41%; R-YW Am ATTYS.

Aug. 1, 1961 M. 1. HULL 2,994,270

ANTI-AIRCRAFT DEFENSE SYSTEMS Filed Jan. 8, 1942 9 Sheets-Sheet 7 IN V EN TOR.

MAURY I. HULL Y I JKQQZJ.

RA. 963M ATTYS.

FIG.21.

Aug. 1, 19 1 M. '1. HULL 2,994,270

ANTI-AIRCRAFT DEFENSE SYSTEMS Filed Jan.- 8, 1942 Q SheetS-Sheet a l N Q'N IN V EN TOR.

lylAURY I. HULL Aug. 1, 1961 M. 1. HULL 2,994,270

ANTI-AIRCRAFT DEFENSE SYSTEMS Filed Jan. 8, 1942 e Sheets-Sheet 9 :8 Q I I4 742 INVENTOR.

lQ/IAURY I. HULL United Maury I. Hull, Washington, no, assi nr to the United States of America as represented by the Secretary of the Navy Filed Jan. 8, 1942, Set. No. 426,086 15 Claims. (Cl. 102'49) This invention relates to the structural features of new and novel rockets which may be guided toward a target such, for example, as aircraft, and a continuation-in part of my application Serial No. 377,398, filed January 21, 1941, now abandoned. I I

It has been found to be desirable in the held of military rockets which are adapted for use in certain types of warfare such, for example, as anti-aircraft defense to provide the rocket with certain structural features which will cause the rocket to be guided by remote control to the target.

Accordingly, one object of my invention is to provide a rocket which will follow a beam of light which is continuously shifted to remain focused on enemy aircraft.

Another object of the instant invention is the provision of a rocket which may be continuously steered by the rays of a beam of modulated light.

A further object is the provision of a rocket which is capable of being directed along a desired t'raje'ctlor'y by directing the rays of light of various spectfa upon the rocket and altering the spectra of the light so as to maintain the rocket upon the desired trajectory.

Still another object of the instant invention is the provision of a rocket which may be steered by apparatus sensitive to radio frequency signals transmitted from a remote control station.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by referenceto the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is an elevation view of a rocket which may be used in accordance with the principles of my invention;

FIG. 2 is a view of the interior structure of the rocket of FIG. 1;

FIG. 3 is a bottom plan view of the rocket shown in FIG. 2 revealing the positions of the rudders and photo= electric cells incorporated in the base of the rocket;

FIG. 4 is a sectional view of a portion of the tail section of a rocket in accordance with another form of my invention wherein gas pressure is utilized to move the steering rudders of the rocket;

FIG. 5 is a vertical sectional view of a valve which may be utilized to control the fluid pressure of the gas which is used in the rocket of FIG. 4;

FIG. 6 illustratively discloses the manner in which a portion of a control circuit of FIG. 21 may be adapted to control the rocket of FIG. 4;

FIG. 7 is an elevational View partly shown in section to show some of the interior elements of a rocket in accordance with another form of my invention in which the steering rudders are dispensed with, the rocket being steered by changing the angular setting of the exhaust vent relative to the longitudinal axis of the rocket and includes apparatus for forcibly ejecting a charge of explosive from the rocket at a selected time;

FIG. 8 is a view of the rocket taken on line 8-8 in FIG. 7;

FIG. 9 is a bottom plan view of the rocket shown in FIG. 7;

FIG. 10 is an elevation view with parts broken away to show the placement of a folded para'chute' in'the rocket and the mechanism for releasin the parachute} FIG; 11 is a showing or the rocket descending to the tates Patent 0 F 2,994,270 Patented Aug. 1, 1961 earth after the parachute shown in FIG. 10 has been re leased;

12 is a diagrammatic showing of the electrical circuit of preferred form utilized to control the parachute releasing mechanism shown in FIG. 10; V p

FIG. 13 shows a portion of a rocket as viewed from line 13-13 of FIG. 14 and which may be steered by con} trolling the emission of gas under pressure from a plurality of side openings or vents in the casing of the rocket;

FIG. l4 a view in elevation shown partially in section of the fixed combustion chamber utilized in conjunction with that portion of the rocket shown in FIG. 13; i

FIG. 15 shows a portion of the interior of a rocket in accordance with another form of my invention in which a plurality of motors or combustion chambers are operated in cooperation with one another to effect steering of the rocket by having the rate of combustion in one or moreof the chambers altered;

FIG. 16 is a bottom plan view of the combustion chamber arrangement taken on line 1616 of FIG. 15;

FIG. 17 shows a sectional view of one of the valves utilized to effectuate an alteration in the rate of combustion in one or more of the combustion chambers shown in FIGS. 15 and 16;

FIG. 18 shows a portion of a rocket in accordance with another form of my invention wherein a plurality of motors or combustion chambers are used, the exhaust vents thereof being capable of alteration in length thereby causing the rocket to be steered;

FIG. 19 is a schematic diagram showing the manner in which full directional control of a rocket having three motors or three exhaust vents may be obtained;

FIG. 20 is a sectional View of an electrically controlled fuze' which may be used in conjunction with the rocket of the instant invention;

FIG. 21 illustrates in diagrammatic form an electrical control circuit adapted for use with any of the forms of rocket shown and described herein;

FIG. 22 is a diagrammatic showing of a control on cuit involving radio frequency circuitry and circuits for operating the rocket in various manners, to be more fully described hereinafter, and which is used in conjunction with certain portions of the control circuit of FIG. 21;

FIG. 23 is a diagrammatic showing of a radio transmitting circuit adaptable for steering the rocket of my invention along a selectively controlled radio beam; and

FIG. 24 is a diagrammatic view of a modified form of a portion of the circuit shown in FIG. 21 and which will permit the rocket to follow a beam of modulated light during daylight hours. I

Referring now to the accompanying drawings in which like reference numerals are employed to designate like parts, and more particularly to FIG. 1 thereof wherein reference numeral 20 designates the rocket generally, 22'

represents the striker head of a percussion or contact fuz'e which is shown in greater detail in FIG. 2 and which will be more fully explained hereinafter. I p

The striker head is normally held in the position shown by spring 24. However, when the rocket strikes an object such, for example, as a portion of an aircraft, the" striker head 22 is forced downwardly, plunging the tip ing pin 26 into a primer or detonator charge as shown in FIG. 2. Numerals 28 and 30 designate two microphones, microphone 28 having a directional patterri with antenna which may be constructed in any desirable manner such, for example, as of an insulated wire running along the side of the rocket and attached thereto is'shown at 32. An exhaust opening 34 communicates will be more fully described hereinafter. Rudders or steering fins are designated by the numerals 36, 38, and 40.

Reference is now made to FIG. 2, which shows a longitudinal sectional view of the rocket in accordance with one form of my invention and in which the electrically operated fuze, hereinafter described, is omitted from the powder chamber 42 for the sake of clarity. The percussion or contact fuze, hereinbefore mentioned, will now be described in greater detail. A supporting member 44 holds the detonator charge 46 to the interior wall of the rocket casing and at the forward or leading end thereof. Support 44 is provided with a flash hole 48 which, upon the detonation of charge 46, permits the ignition of the main charge, not shown, contained in compartment 42. Floor 50 separates compartment 42 from the remainder of the rocket. For purposes of explanation, a fuze such, for example, as the electrically operated fuze shown in detail in FIG. 20 would normally be positioned upon fioor 50, it being understood that the remainder of the compartment 42 would be filled with explosive, shrapnel, or some other form of lethal charge.

The combustion chamber 52 having flanges or fins 54 for cooling purposes is provided with pipes or conduits 56 and 58 for bringing fuels to the chamber from fuel compartments as will more readily appear as the description proceeds. Upon explosion of the fuel in combustion chamber 52 gases are formed and exhaust from the'co-mbustion chamber through the forked exhaust vent 60 which communicates with ports 34 and 62 in the sides of the rocket. It will be obvious to those skilled in the art that any suitable means such, for example, as valves 64 and 66 may be provided in the pipes 56 and 58, respectively, for cutting the fuel fiow therein on and off. Correspondingly, any suitable means may be used to operate valves 64 and 66 such, for example, as handles 68 and 70.

Below the exhaust vent 60, as viewed in FIG. 2, are three compartments, 72 being adapted for the accommodation of nitrogen gas, 74 for the accommodation of gasoline, alcohol, or other fuel, and 76 for the accommodation of liquid oxygen. Compartments 72 and 74 are interconnected by opening 78 and are filled through opening 80 in the wall of the rocket 20 which is in direct communication with compartment 72. Compartment 76 which is adapted to contain liquid oxygen also has a filler opening 82 in the wall of the rocket. The filler openings 80 and 82 may be closed by any suitable means such, for example, as plugs 84 and 86, respectively. As shown in FIG. 2, pipe 58 is positioned with the lower end thereof near the bottom of and in communication with compartment 74. The pressure of the gas in compartment 74 forces the fuel out of this compartment, through pipe 58, and into the combustion chamber 52. In a similar manner, pipe 56 is positioned so that the lower end thereof is in fluid communication with compartment 76. The pressure of the liquid oxygen in compartment 76 will be suflicient in itself to force the contents of this compartment up pipe 56 and into combustion chamber 52. The liquid oxygen after being forced through pipe 56, and the hydrogen compound fuel, after being forced through pipe 58, violently explode Within the combustion chamber 52, and the reaction of the escape of the gases produced by this explosion against the surrounding atmosphere serves to propel the rocket. It will readily be understood by those skilled in the art that a safety valve may advantageously be included in the wall of compartment 76 to prevent explosion of the rocket should the back pressure become too great.

Immediately below compartment 76, as viewed in FIG. 2, is positioned the apparatus for controlling the rudders. This apparatus includes four electromagnets arranged in such a manner upon the casing of the rocket on the interior side thereof so as to exert pulling effects upon rudders are mounted. The rudders are held in a forward or straight-ahead position by springs when the magnets are not energized. In order that this apparatus for controlling the rudders be more fully understood, the structure incorporated within this apparatus will now be described in greater detail.

Shaft 88 having the arm 90 and shaft 92 having arm 94 connects rudders 36 and 38 and rudders 39 and 40, respectively, as shown in FIGS. 2 and 3, respectively. The rudders 39 and 40 are normally held in a straightahead position by springs 96 and 98 pulling on arm 94. However, when the magnet 100 is energized, arm 94 is pulled to the left, and when magnet 102 is energized, arm 94 is pulled to the right, as viewed in FIG. 2. Similarly, when magnet 104 is energized, a pull is exerted upon arm 90, which, when moved, correspondingly moves rudders 36 and 38. A companion magnet, not shown for the sake of clarity, is provided in a diametrically opposing relationship to magnet 104 to exert a pulling effect upon arm 90 in a direction opposite to that exerted by magnet 104 when the former magnet is energized. Similarly, springs, not shown, hold arm 90 so that the rudders 36 and 38 are in a straight-ahead position when neither the magnet 104 nor the magnet diametrically opposed thereto is energized. The apparatus for controlling the energization of the electromagnets, hereinbefore described, is operatively mounted within the body of the rocket, and in the forward end of the chamber or compantment 106.

At 108, 110, 112, and 114 are shown photoelectric cells of any suitable type such, for example, as photo-conductive cells, plugged into insulated sockets 116, 118, 120, and 122, respectively. Covers or windows made, at least partially, of glass or a similar suitable material are threaded into the tail end of the rocket, as shown in FIG. 2, and are designated by numerals 124, 126, 128, and 130, respectively. These covers may be of colored or uncolored glass depending upon the desired mode of operation of the rocket in a manner which will be more readily apparent as the description proceeds. The wall of the rocket may extend downwardly somewhat as shown by numeral 132, in FIG. 2, to provide a shield for the photoelectric cells from the flare of the rockets exhaust.

FIG. 3, which is a bottom plan view of the rocket of FIG. 2, shows the placement of the rudders 36, 38, 39, and 40, the six photoelectric cells 108, 110, 112, 114, 115, and 117, and the glass covers or windows 124, 126, 1 28, 130, 131, and 133, respectively.

Referring now to FIG. 4 which shows another form of the rocket of my invention it will be observed that the magnets of the form of the rocket shown in FIG. 2 have been replaced by two pairs of pistons as the means for moving the rudders. The shaft 134- passes through the body of the rocket and supports rudders 39 and 40 in a manner similar to that disclosed in FIG. 2. Cylinders 142 and 144 which contain pistons 146 and 148, respectively, are secured to the wall 136 of the rocket by suitable brackets 138 and 140. Piston rod 150 and flexible coupling 1'52 together with arm 154 connect pistons 146 and 148 to shaft 134 so that any motion of the pistons will cause the shaft 134 to be rotated thereby causing the rudders of the rocket to be turned. Springs 96 and 98 normally hold the rudders in a straight-ahead position when there is no gas pressure in the cylinders.

. Cylinders 142 and 144 are connected by pipes 156 and 158 with the compartment 72 containing gas under pressure. Valves 160 and 162 control the admission of the gas to the two cylinders, respectively, and valves 164 and 166 connected with cylinders 142 and 144, respectively. by pipes 168 and 170 control the exhaust of the gas from the cylinders. It will be understood by those skilled in the art to which the instant invention pertains that suitable openings such, for example, as that shown at 172 will be provided in the body of the rocket to allow the gas to escape therefrom to the surrounding atmosphere in a manner which will not afiect the flight of the rocket. Valve 160 which may be identical to valves 162, 164, and 166 is shown in vertical section in FIG. 5. The valve inlet and valve outlet portions of pipe 156 communicate.

with one another only through opening 174 which is normally closed by the stopper 176 which may be composed of any suitable material such, for example, as rubber and which is securely attached to the rod 178 having a flange 180 secured thereto. Spring 182 pressing against flange 180* maintains stopper 176 in a tightly pressed condition against the portion of the valve casing which defines the opening 174 except when solenoid 184 is energized. Upon energization of solenoid 184, rod 178 is pulled into the solenoid, and the opening 174 permits gas to flow through pipe 156 into cylinder 142. When solenoid 184 is de-energized, the valve resumes its closed position due to the action of spring 182.

FIG. 6 shows the electrical circuit for controlling the pistons hereinbefore mentioned and is a modification of a portion of the circuit disclosed in FIG. 21 to be described more fully hereinafter. Relays 186 and 188 of FIG. 6 may be substantially identical with relays 476 and 480 of FIG. 21 except that there are two contacts on each relay in FIG. 6. One of these two contacts is closed while the other contact is open, when the relay is energized. A spring may be normally utilized to hold the armature against the upper contact of the relay. When the relay is energized, the armature moves downwardly and remains in the downward position so long as the relay remains energized. Relay 186 is energized when light reaches cell 108 in greater intensity than the light which reachm cell 114, and relay 188 is energized when light reaches cell 114 in greater intensity than that which reaches cell 108, as will be more fully explained hereinafter in connection with the description of FIG. 21.

The operation of this form of my invention will now be described in detail. With the rocket following the beam of light and located in the center thereof, relays 186 and 188 are both de-energized and, therefore, the upper contacts of both relays are closed so that the solenoids 190 and 192 associated with valves 164 and 166, respectively, are energized and, consequently, valves 164 and 166 are open. Supposing now that the beam of light shifts slightly, thereby causing the light intensity reaching cell 108 to be greater than that reaching cell 1l1l4 and causing relay 186 to be energized, valve 160 is opened and valve 164 is closed as the relay 186 is closed with respect to its lower contact and opened with respect to its upper contact. Gas flowing into cylinder 142 through pipe 156 develops a pressure behind piston 146 of suflicient magnitude to cause movement thereof, thereby moving rod 150 and arm 154 to the right which in turn rotates shaft 134 to effect a setting of the rudders 39 and 40 which will cause the trajectory of the rocket to be changed in the desired manner. When the rocket has moved back into the center of the beam of light, relay 186 is de-energized, valve 160 closes and valve 164 opens thereby permitting the gas in cylinder 142 to escape and spring 96 to bring the rudder back to its original or straight-ahead position.

It should be observed that in FIG. 2 magnet 100, upon energization, exerts a pulling effect upon arm 94, whereas in FIG. 4, magnet .184, when energized, causes certain valves to be activated which results in the arm being pushed away from this magnet. Therefore, the relative positions of cells 108 and 114 and magnets 184 and 194 must be reversed to assure that the rocket will be turned in the proper direction to equalize the intensity of light reaching cells 108 and 114.

It is contemplated that a second set of cylinders at right angles to the set comprising cylinders 142 and 144 may be placed beneath the hereinbefore described set. The second set of cylinders include pistons identical to those used with the first set of cylinders and connected 6 to arm 90, shown in FIG. 4, to thereby control the movement of rudders 36 and 38. This second set of cylinders and pistons is controlled by a pair of relays in a similar manner to that by which the first set of cylinders and pistons are controlled by relays 186 and 188.

Referring now to FIGS. 7, 8, and 9 which show a rocket in which the movable rudders or steering vanes utilized in the forms of my invention illustrated in FIGS. 1 to 4, inclusive, have been eliminated and the direction of flight of the rocket is changed by changing the angular setting of the exhaust vent of the combustion chamber relative to the longitudinal axis of the rocket it will be observed that the wall of the rocket of FIGS. 7, 8, and 9 is not cylindrical throughout as in the forms heretofore described. Instead, the rocket of this form of my invention is provided with four posts 196, 198, 200 and 202 substituted for a portion of the cylindrical wall of the other forms of the rocket hereinbefore described. These posts may be joined in any convenient manner to the other portions of the rocket such, for example, as by welding. Combustion chamber 204 is mounted in the center of the metal plate 50 which may also serve as the floor of the chamber 42 containing an explosive charge 51. A piece of spring metal 206, connecting the exhaust vent 208 and combustion chamber 204 to plate 50 permits the chamber and exhaust vent to be moved slightly off of the longitudinal axis of the rocket by one of the magnets shown in FIG. 8, to be more fully described hereinafter. At 210 and 212 are shown connections which may be of any suitable type such, for example, as ordinary steam hose and which connect the combustion chamber 204 with the pipes 56 and 58, respectively, which bring the fuel and oxidizing material to the combustion chamber 204. A circular ring 214 connects the four posts upon which the magnets are mounted.

A large cylinder of explosive and shrapnel 244 is releasably mounted within the tail end of the rocket and is arranged to be released upon the energization of magnet 246. It is intended that the head or upper end portion of the rocket contain only enough explosive to effectively cripple or destroy an aircraft provided the rocket actually hit the aircraft and was detonated by the contact fuze hereinbefore mentioned. The main body of explosive will be that designated by numeral 244. The arm 248 which is attached to the main body of explosive 244 passes upwardly through an opening in rib 250. Spring 252 to which is attached a metallic member 254 normally presses against arm 248 with sufficient pressure to tend to force this arm downwardly and outwardly, as viewed in FIG. 7, in a rapid fashion. A latch consisting of rod 256 with flange 258 has a spring 260 pressing against the flange thereby tending to force the rod 256 into a recessed portion 262 of arm 248 to prevent arm 248 from being moved. The latch is constructed and arranged to be operated by magnet 246 which, when energized, pulls the rod 256 into the solenoid 246 and thereby releases the arm 248. As the charge 244 moves outwardly of the casing of the rocket, the element 264 which is the control of a time delay fuze of any convenient design, trips against the element 266 thereby activating the fuze and exploding the charge 2'44 after the rocket has moved a predetermined number of yards from that point on the trajectory at which the time delay fuze became activated. Compartments 268 and 270 are provided for the accommodation of electrical apparatus.

FIG. 8 is a view of the steering arrangement looking upwardly from line 88 of FIG. 7. The magnets 216, 218, 220 and 222 are arranged to exert pulling effects upon metallic pieces 224, 226, 228, and 230 shown in FIG. 8. These metallic pieces are attached in any suitable manner such, for example, as by welding to the exhaust vent 208. Springs 232, 234, 236, and 238 maintain the exhaust vent in a straight-ahead position when none of the magnets are energized, and return the exhaust vent to a straight-ahead position when all of the magnets arede-energized. These springs have not been shown inFIG. 7 for the sake of clarity.

FIG. 9 which is a bottom plan view of the rocket of FIG. 7 shows the photoelectric covers 124, 126, 128, 130, 131, and 133. It is contemplated that the material of the rocket may be designed so that the rocket will not be unbalanced by the unsymmetrical arrangement of the fixed photoelectric cells and their covers.

Operation of the rocket shown in FIGS. 7, 8, and 9 will now be described. Magnets 216 and 220 are controlled by photoelectric cells 108 and 114 in a circuit such, for example, as that illustrated in FIG. 21, to be described hereinafter. However, it should be noted that the relationship of cell 108 to magnet 220 and that of cell 114 to magnet 216 are reversed from those shown in FIG. 2. In FIG. 7, for example, cell 108 is on the opposite side of the rocket from magnet 220 whereas in FIG. 2 the converse is true. Light from a suitable searchlight apparatus which reaches cell 114 in greater intensity than that reaching cell 108 energizes magnet 216 which points the exhaust vent so that the rocket moves in a direction to equalize the intensity of the light reaching the cells 108 and 114.

Instead of employing a separate compartment 72 as shown in FIG. 2 for containing gas under pressure to force the alcohol or other fuel into the combustion chamher, the rocket of FIG. 7 utilizes a piston 240 with one or more piston rings 242. The pressure of the liquid oxygen or other liquid under a relatively high pressure incompartment 76 against the piston 240 maintains an approximately equal pressure on the alcohol or other liquid in chamber 74 thereby forcing the liquid in this last mentioned chamber up the pipe 56 and into the combustion chamber 204.

Referring now to FIGS. 10, 11, and 12, wherein the use of a parachute is disclosed, it will be understood that, by the utilization of this feature, the rocket is capable of gentle'descent to the earth after its charge has been exploded or dropped, thereby permitting the rocket to be used again after an inspection has been made for injury thereto and any repairs needed have been made. It is contemplated that the features shown in FIGS. 10, 11, and 12 may be utilized in conjunction with any and all of the rockets herein shown and described. The parachute, in folded condition, may occupy a compartment under the forward end portion, as viewed in FIG. 10, or beneath the fuel tanks of the rocket. In FIG. 10, for example, the forward or head end portion which carries the explosive charge is supported upon the remainder of the rocket by posts 196, 200, and 202, which are held to the body of the rocket by a metallic band 272. These supports or posts may be of any desired length and their purpose is to remove the charge as far as possible from the body of the rocket so that the resulting explosion of the charge carried in the forward end of the rocket will damage the rocket as little as possible.

FIG. shows, with other structure, the parachute compartment having the parachute folded therein and the apparatus for ejecting the parachute. The wall of the rocket is provided with a door 274 hinged at 276 the door'being normally latched shut by the rod 278 and held in the closed position by the compression of the spring 280 one end of which engages flange 282 of the rod 278 and the other end of which engages one end of solenoid 284. When the solenoid 284 is energized, a downward pull is exerted against rod 278 thereby unlatching the door 274. Then the parachute 286 is forced against the door 274- by springs 280 thereby opening the door and permitting the parachute to be ejected from the body of the rocket. Theparachute 286 may be attached to the rocketby any convenient means such, for example, as by rope2'88', shownin- FIG. 11.

Reference is now made to FIG. 12 wherein a circuit for energizing solenoid 284 is shown. A pressure operated switch, shown generally by numeral 290, is opera" tively positioned in the wall of'one of the pipes which conducts material or fuel to the combustion chamber such, for example, as in pipe-56. So long as the pressure in pipe 56 which is dependent upon the fuel flowing from one of the fuel tanks is sufliciently great, the element 292 which supports contact 294 is pressed toward the left thereby preventing the circuit from being closed. However, should the pressure in pipe 56 be diminished below a predetermined value contacts 294 and 296 are brought into engagement by the action of spring 298 thereby closing the circuit and energizing the solenoid 284 through battery 300, providing switch 302 is closed. The circuit is completed through the element 292, the spring 298, and the pressure. operated switch housing 304.

The solenoid 284 may also be energized as a result of the operation of the time delay relay 306. The time delay period is so chosen that the solenoid 284 will beenergized at the time when the fuel of the rocket has been substantially consumed. It will be understood that switch 308 is closed prior to firing the rocket.

It will be obvious to those skilled in the art that the parachute may include any convenient means for opening itself when the parachute isstruck' by the passing atmosphere such, for example, as providing a 'rip'c'ord which is so short that it is pulled due to the motion of the parachute during the ejection thereof from the body of the rocket.

Another form of my invention is shown in FIGS. 13'

and 14 which illustrate the portions of a rocket generally similar to that of FIG. 7. However, in this form of the rocket the combustion chamber 310 is fixed and the exhaust gases pass from the combustion chamber through four pipes which are positioned above the combustion chamber and below the explosive head and arranged in the form of a cross in a plane which is normal to the longitudinal axis of the rocket. Each pipe is provided with a valve similar to that disclosed in FIG. 5. A small pipe 312 connects the combustion chamber 310 to the four valves 314, 316, 318, and 320 through pipes 322, 324, 326, and 328, respectively, thereby providing a conduit for the passage of exhaust gases from the combustion chamber to these valves. A magnet is operatively associated with each of these valves and is energized in a manner similar to those hereinabove described and illustrated in FIG. 5.

When one of these valves is opened, the exhaust gas under pressure escapes through the opening thereof and passes through the wall of the rocket into the surrounding atmosphere thereby turning the rocket in the desired direction until certain conditions such, for example, as the intensity of the light reaching the photoelectric cells are equalized. If the rocket is to be guided upon a light beam, the valves and photoelectric cells will be properly related to provide the desired turning action. For example, the photoelectric cell 108 will be positioned on the opposite side of the rocket from that on which magnet 220 of FIG. 11 and valve 320 are mounted.

Referring now to FIGS. 15 and 16 wherein portions of a rocket generally similar to that of FIG. 7 are shown. it will be observed that four substantially identical or similar motors or combustion chambers are utilized, the steering effect thereof being obtained by disturbing theequilibrium of forces generated thereby. FIGS. 15 and 16 show a metallic plate 330' mounted between four posts 196, 198, 200, and 202 with four combustion chambers 332, 334, 336, and 338 mounted upon this plate and equidistant from the center thereof. Post 198' is not shown in FIG. 15 for the sake of clarity. The pipe 340 is provided to bring. oxygen to all of these motors or combustion chambers from the fuel tanks of the rocket, and the individual pipes 342, 344, 346, and 348 are provided to bring alcohol or other fuel from the fuel tanks of the rocket.

FIG. 15 is a side view of a portion of the rocket in accordance with this form of my invention wherein valves 350, 352, and 354 are shown to be positioned within the pipes 342, 344, and 346, respectively, which bring alcohol or other fuel of a suitable character to the combustion chambers 338, 334, and 332, respectively. Conduit 356 connects the center of the individual pipes 342, 344, and 346, as shown in FIG. 15, to the fuel tank so that the fuel will reach the combustion chambers 332, 334, and 338 in equal volume and pressure. So long as the motors or combustion chambers are identical and generating equal forces, the rocket will move in a straight-ahead direction. However, if any one of the motors or combustion chambers produces a force less than that of the other three, the rocket will tend to turn toward the side on which the smaller force was produced. Therefore, it is contemplated in this form of my invention that steering may be effected by temporarily damping the operation of one or more of the combustion chambers by decreasing the fuel supply thereof. Upon a decrease of the fuel supply of one of the combustion chambers, a smaller force will be exerted by the exhaust gases of this combustion chamber against the surrounding atmosphere than that exerted by the exhaust gases of the other combustion chambers thereby causing the rocket to be turned.

Reference is now made to FIG. 17 wherein a vertical sectional view of one of the valves such, for example, as valve 354 is shown. It is to be understood that the other valves 350 and 352 are similar in construction to that disclosed in FIG. 17. Upon energization of magnet 358, rod 360 will be pulled to the left, as shown in this figure, thereby moving the larger portion 362 of the rod into the passage of the pipe 346 and removing the smaller part 364 or rod 360 therefrom. It will be apparent that this larger portion 362 retards the flow of fuel but will not stop the flow altogether. Upon de-energization of magnet 358, spring 364, now in compression, will exert a pushing action against flange 366 to return the valve member to the original position thereof. The photoelectric cell 108, in this form of my invention, may be on the same side of the rocket as that upon which magnet 358 is mounted.

FIG. 18 shows a portion of another form of the rocket of my invention which includes a plurality of substantially identical combustion chambers and exhaust vents therefore. Although it is contemplated that four combustion chambers be used, only two combustion chambers 368 and 370 are shown in this figure for the sake of simplicity and clarity. The unbalancing of a pair of combustion chambers and the exhaust vents thereof which is required to turn the rocket in one plane is accomplished by changing the length of one of the exhaust vents relative to the length of the exhaust vent of the other combustion chamber in this plane. As will be observed from an inspection of FIG. 18, the exhaust vents 372 and 374 have short extensions 376 and 378, respectively, arranged to telescope within the main exhaust vents 372 and 374. The pressure of the exhaust gases against the upper surfaces of these extension members 376 and 378 normally maintains these extension members in the lowermost position thereof which is determined by the inwardly extending flanges 380 and 382, respectively, on the lowermost ends of the main exhaust vents 372 and 374, respectively. The springs 384 and 386 which are normally under tension tend to equalize the pressure of the exhaust gas. However, should one of the magnets such, for example, as magnet 388 be energized, arm 390 will be subjected to a pulling effect thereby telescoping the extension member 376 into the main exhaust vent 372 thereby causing the force exerted by the exhaust gases of the main exhaust vent 374 against the surrounding atmosphere to be decreased to a magnitude which is less than that being exerted by the exhaust gases of the main exhaust 372. When the magnet 388 is de-energized, the pressure of the exhaust gas returns the exhaust vent extension member 376 to its original position. The operation of the other the manner shown.

combustion chambers and exhaust vents is identical to that of combustion chamber 368 and the exhaust vent 372, hereinbefore described. The lower ends of the exhaust vents 372 and 374 as well as those exhaust vents not shown are provided with longitudinal slots 392 and 394, respectively, through which arms 390 and 391, re-- spectively, extend. v

The position of magnets 388 and 389 relative to that of photoelectric cells 108 and 114 and the battery 438 are so chosen as to provide the desired turning of the rocket upon a predetermined signal being received thereby. The explosive head of the rocket and the fuel tanks thereof may be toward the forward end and toward the tail end, respectively, of the rocket in accordance with this form of my invention similarly as described in connection with that form disclosed in FIG. 7. Any convenient means may be utilized for supplying the combustion chambers with a proper fuel. Referring now to FIG. 19 wherein is shown the manner in which one motor or combustion chamber may be eliminated when it is desired to control the rocket by a radio beam only, it will be observed that the three combustion chambers 396, 398, and 400, utilized herein, are positioned so as to be equally spaced such as at 120, for example. In this form of my invention the circuit of FIG. 21, to be more fully described hereinafter, will be altered by eliminating relay 530 and those portions of this circuit associated with the photoelectric cells. The magnets 100, 102, and 105 of FIG. 21 will control the motors or combustion chambers 396, 398, and 400, respectively. It will be apparent from an examination of FIG. 19 that the rocket may be made to turn in six directions by damping or accenuating one or two of the motors at a time. If the motor or combustion chamber 396 alone is damped, the rocket will turn in direction 402. To turn the rocket in direction 404 the combustion chamber 398 is damped. Should the combustion chamber 400 be damped, the rocket will be turned in direction 406. If combustion chambers 396 and 398 are simultaneously damped, the rocket will turn in direction 408. The rocket will be turned in direction 410 upon simultaneous damping of combustion chambers 398 and 400. Should the combustion chambers 396 and 400 be simultaneously damped, the rocket will turn in direction 412. Simultaneous damping may be accomplished by closing two switches, such, for example, as 722 and 724 of FIG. 23, hereinafter described, thereby causing the radio frequency to be modulated at two audio frequencies. As a result of closing these two switches, there will be audio frequency components of two frequencies in the output of tube 540 of FIG. 21 which will cause the two relays and 102 to operate.

Referring now to FIG. 20 wherein the electrically controlled fuze, to which reference has been made hereinbefore, is shown in cross-section and which is generally designated by numeral 414, it will be understood that this fuze may occupy any convenient space in compartment 42 of the rocket such, for example, as being fastened to the floor 50 of compartment 42 in FIG. 2. The primary charge or detonator is designated in FIG. 20 by numeral 416. The fuze casing 418 is provided with a flash hole 420 thereby enabling the primer charge 416 to detonate the main charge of powder contained in compartmen-t 42 of the rocket 20. The firing pin 422 is normally held away from the primer charge due to the fact that a groove 424 in pin 422 is engaged by rod 426 in This coatcion between rod 426 and pin 422 prevents the spring 428 which presses against flange 430 of pin 422 from forcing the pin forward into the primer charge. When rod 426 is withdrawn from the groove in pin 422, the spring forces the firing pin into the primer charge. When the firing pin 422 strikes the primer charge 416 an explosion results the flash of which passes through flash hole 420 and detonates the main charge in compartment 42 of the rocket. Rod 426 is normally held in the groove of pin 422 by spring 432 l l pressing against a circular flange 434'. However, when sol'ehoidrnagnet 436' becomes energized from battery 586 of FIG. 21 as will be more fully understood from'the description of FIG. 21 appearing hereinafter, rod 426 moves upwardly thereby releasing pin' 422 and causing the primer charge 416 to be exploded.

Referring now to FIG. 21 which shows an electrical circuit of preferred form which may be utilized to operate the hereinbefore mentioned electromagnets, it will be observed that photoelectric cells 108 and 114 have a potential supplied to them by battery 438. The current from battery 438 flows through resistance 440 to photoelectric cell 108 and through an equal resistance 442 to photoelectric cell 114. Two vacuum tubes, which may be identical, are shown at 444 and 446, the grid of tube 444 being connected to one end of the resistance 440 and to photoelectric cell 108, and the grid of tube 446 being connected to one end of resistance 442 and photoelectric cell 114. If the switch shown at 448 is open, the grid circuit of vacuum tube 444 is comprised of the grid of vacuum tube 444, resistance 440, resistance 450, battery 452, switch 454, switch 456, resistance 458, and battery 460, it, of course, being understood that suitable electric conductors interconnect the grid to resistance 440 and battery 460 to the filament of tube 444 as well as interconmeeting the various elements mentioned with one another as shown in FIG. 21. The grid circuit of vacuum tube 446 is identical with that of tube 444 except that resistance 442 replaces resistance 440. The combined potentials of batteries 452 and 460 is sufficient to permit operating conditions to be attained under which no grid current flows in vacuum tubes 444 and 446 at any time. The plate circuit of vacuum tube 444 includes resistance 462 and battery 464, and the plate circuit of vaccum tube 446 includes resistance 466 and battery 464. The resistances 462 and 466 may be of equal values. The grid circuit of another vacuum tube 468 includes battery 470 and resistances 462 and 466, and the grid circuit of still another vacuum tube, designated by numeral 472, includes battery 474 and both resistances 462 and 466. Batteries 470 and 474 are themselves of suficient potential to bias tubes 468 and 472, respectively, so that no grid current flows in either tube 468 or 472 at any time. The plate circuit of vacuum tube 468 includes the winding of relay 476 and the battery 478, while the plate circuit of vacuum tube 472 includes the winding of relay 480 and battery 482. All of the relays shown in the drawings are, unless specifically stated otherwise, of the conventional type in which the armature is normally held away from the core by a slight spring tension. In this type of relay the armature swings toward the core when the relay winding is energized and remains in this position until the relay winding is de-energized at which time the armature swings back to its former position. If switches 484 and 486 are closed and the windings of relays 476 and 480 are energized, the contacts of these relays will close and cause the energization of magnets 100 and 102, respectively, through batteries 488 and 489 respectively.

This portion of the circuit of FIG. 21 is designed to provide an efiicient control of the rudders 39 and 40 shown in FIG. 3. During the operation of this portion of the circuit the vacuum tubes 444 and 446 may be biased by the combined potentials of batteries 452 and 460 so that some plate current flows at all times. If resistances 440 and 442 are equal, and the photoelectric cells 108 and 114 are identical, the voltage drop across resistance 440 will be equal to that across resistance 442 when light reaches the photoelectric cells 108 and 114 in equal intensity. If tubes 444 and 446 are identical,

and resistances 462 and 466 are of equal value, the voltage drop across resistance 462 will be equal to that across resistance 466 when equal voltages are applied to the grids of vacuum tubes 444 and 446, provided tubes 468 and 472 are so biased that they draw no grid current. So long as the voltage drops across resistances 462 and 12 466 are equal, no effective voltage will be introduced into the grid circuits of tubes 468 and 472, because the voltage drop across resistance 462 tends to make the grid of tube 468 negative and the grid of tube 472 positive, while the voltage drop across resistance 466 tends to make the grid of tube 472 negative and the grid of tube 468 positive. Tubes 468 and 472 are so biased by batteries 470 and 474, respectively, that when the voltage drops across resistances 462 and 466 are equal and opposite, there is insufficient plate current flowing in tube 468 to operate relay 476, and likewise, there is in sufficient plate current in tube 472 to operate relay 480, and, therefore, there is no charge in the position of rudders 39 and 40.

FIGS. 2 and 3 should also be considered in connection with the description of the operation of this portion of the circuit of FIG. 21, hereinbefore described. Assum' ing that the rocket is ascending in a substantially vertical direction, as shown in FIG. 2 and is so positioned'as to be directly in the center of the beam of light emitted from any suitable Searchlight apparatus, light will reach photoelectric cells 108 and 114 in approximately equal intensity. If switches 451, 454, and 456 of FIG. 21 are closed and switch 448, also of FIG. 21, is open so that the grid circuit of tube 444 contains resistance 440, battery 452 having a negative bias, resistance 458', and battery 460 having a negative bias, and, at the same time, the grid circuit of tube 446 contains resistance 442, battery 452, resistance 458, and battery 460, light reaching photoelectric cells 108 and 11-4 in approximately equal intensity will cause equal current flow in resistances440 and 442 which develops equal voltage drops across these resistances, these voltage drops being of such polarity as to place a'negative potential on the respective grids of these tubes. The effective bias on tubes 444 and 446 is the sum of potentials of batteries 452 and 460 plus the voltage drop across resistance 440 or 442. Since, in this situation, the grid voltages of tubes 444 and 446 are equal, their plate currents are equal, and the voltage drops across resistances 462 and 466 are equal, no effective voltage is introduced therefrom into the grid circuit of either of tubes 468 or 472, and relays 476 and 480 remain de-energized.

Supposing now that the beam of light shifts slightly to the right of FIG. 2 so that light reaches photoelectric cell 114 in greater intensity than it reaches photoelectric cell 108, the current through cell 114 will increase in proportion to that through cell 108. This results in a voltage drop across resistance 442 which will exceed that across resistance 440, the negative grid potential of tube 446, in turn, becoming greater than that of tube 444, the plate current of tube 444 becoming greater than that of tube 446, and the voltage drop across resistance 462 becoming greater than that across resistance 466. As hereinbefore stated, the voltage drop across resistance 462 tends to make the grid of tube 472 positive, while the voltage drop across resistance 466 tends to make the grid of tube 472 negative. In this situation in which it is assumed that the direction of the rocket has shifted relative to the direction of the light beam, and the volt age drops across resistances 440 and 462 being unequal and opposite to those across resistances 442 and 466; respectively, an effective positive voltage is introduced into the grid circuit of tube 472 which increases the plate current. Similarly, an effective negative voltage is introduced into the grid circuit of tube 468, thereby increasing the bias thereof. Relay and circuit constants are so chosen that a very slight increase in plate current in tube 472 results in the energization of relay 480. Upon energization of relay 480 the contacts thereof are closed and magnet 102 is energized through battery 489. Energization of magnet 102 causes a change in the position of rudders 39 and 40 to be effected thereby turning the rocket toward the right so that it moves back into the center of the light beam. When the rocket has 13 moved to the right suificiently far so that the light again reaches cells 108 and 1-14 in equal intensity, relay 480 is de-energized as the voltages across resistances 462 and 466 become equal.

In a similar manner, had the rocket changed itsdirection relative to the direction of the beam of light so that the light would have been to the left of the rocket, photoelectric cell 108 would have received illumination of greater intensity than that received by photoelectric cell 114, relay 476 would have been energized in a manner similar to that hereinbefore described for the energization of relay 480. Energization of'relay 476 would result in the activation of magnet 100 which would have changed the position of rudders 39 and 40 so as to turn the rocket to the left thereby bringing the rocket back into the center of the light beam.

The photoelectric cells 115 and 117, which may be identical photo-conductive cells, have circuits associated with them containing apparatus similar in all respects to the circuits hereinbefore traced with respect to cells 108 and 114. It will be clear from the circuit as shown in FIG. 21 that when light reaches cell 115 in greater intensity than that reaching cell 117, relay 490 is energized, energizing magnet 105 through battery 492, assuming that switch 494 is closed. Conversely, when light reaches cell 117 in greater intensity than that reaching cell 115, relay 496 is energized, energizing magnet 104 through battery 498, provided switch 500 is closed. The positionof rudders 36 and 38 is controlled by magnets 104 and 105 to effect a steering of the rocket in. a plane normal to the plane in which steering of the rocket is controlled by cells 108 and 114.

The photoelectric cell 110 and the vacuum tube 502 have two functions which are as follows:

(1) To provide a means for automatically controlling the sensitivity of the photoelectric cell circuits which steer the rocket so that their sensitivity will be more nearly uniform over the entire range of the rocket, and

(2) To permit the positive steering of the rocket by a modulated light beam.

The photoelectric cells 110 and 112 together form a device for exploding the electrically controlled fuze, shown in FIG. 20, this function being carried out by a portion of the circuit of FIG. 21 in a manner to be hereinafter described.

The grid circuit of tube 502 contains resistance 504, relay 506, a bias battery 508, and suitable electrical conductors connecting the grid of tube 502 to resistance 504, resistance 504 to relay 506, relay 506 to battery 508, and battery 508 to the filament of tube 502. The contacts of relay 506 are normally maintained in the closed position until the relay is energized. The poten: tial of battery 508 alone is sufficient to make the tube 502 operate on the straight line portion of the static characteristic curve, and no grid current flows. The plate circuit of tube 502 contains switch 510, resistance 450 which is shunted by switch 451, switch 512, resistance 514 which is shunted by switch 516, battery 518, and electrical conductors of a suitable type interconnecting said elements between the plate of tube 502 and the filament thereof. As hereinbefore stated, when switch 451 is open, resistance 450 is in the grid return circuit of tubes 444, 446, 520, and 522.

The use of photoelectric cell 110 makes possible the provision of a sensitivity control which will now be described. The current flowing through the cell 110 from battery 523 causes a voltage drop across resistance 504 which tends to impress a positive potential on the grid of tube 502. The greater the intensity of illumination reaching cell 110, the greater the current passing through resistance 504, and the larger the positive voltage intro-- duced into the grid circuit of tube 502, which makes for a larger plate current in tube 502. If'switch 451 is open and switch 512 is closed, this plate current flows through resistance 450 when switch 510 is closed upon the lower contact thereof. The flow of plate currentthrough resistance 450 causes a voltage drop which tends to place a negative potential on the grids of tubes 444, 446, 520, and 522, and to thereby increase the bias of these tubes. As the rocket moves farther from the source of light, the illumination of cell 110 continuously decreases, thereby increasing the negative potential on the grid of tube 502, decreasing the plate current, decreasing the voltage drop across resistance 450, and decreasing the negative bias applied to tubes 444, 446, 520, and 522.

The manner in which a modulated beam of light may be used to steer the rocket will now be described. In addition to the set of relays hereinbefore described, FIG. 21 also shows another set of sensitive relays 524, 526,- 528, and 530 whose contacts close when energized andwhich, when switches 532, 534, 536, and 538 are closed, have their contacts in parallel with the contacts of relays 476, 480, 490, and 496, respectively, so that magnet may be energized as a result of the operation of either relay 476 or 524. Likewise, magnet 102 may be energized as the result of the operation of either relay 480 or 526, and, in alike manenr, magnet 105 may be energized by the operation of either relay 490 or 528. Similarly, magnet 104 may be energized by the operation of either relay 496 or 530. As presently contemplated, relays 524, 526,528, and 530 are alternating current relays whose windings are especially designed to have specific inductances, and the inductance of each relay winding may be different from that of the other relay windings. Vacuurntube 540 has its plate current supplied by battery 542. An audio choke 544 is connected between battery 542 and the plate of tube 540. This choke 544 has a high impedance at the lowest audio frequency to be used. The audio by-pass condenser 546 has a low impedance at the lowest audio frequency to be used. Each of the relays 524, 526, 528 and 530 has in series with its winding a condenser 548, 550, .552, and 554, respectively, the values of capacity of which are so chosen that the inductance of each relay winding with its condenser constitutes a series resonant circuit having minimum impedance at a definite audio frequency. If switches 556 and 558 are closed, these series resonant circuits are all connected in parallel with choke 544 through condenser 546. Each series resonant circuit is characterized by being responsive to a different frequency than that of any of the other series resonant circuits, so that an audio frequency component of plate current in tube 540 of a certain frequency will energize only one of the relays.

When it is desired to steer the rocket by a modulated beam of light, switch 510 in the plate circuit of tube 502 may be closed on its upper contact, switches 560 and 562 closed on their upper contacts, switch 564 closed and switch 516 opened. It will be observed that the position of switch 512 is immaterial. the plate circuit of tube 502 may be traced as follows: from the plate of tube 502 to switch 510, to switch 560, to switch 564, through resistance 514, through battery 518, and to the filament of tube 502. The resistance 514 becomes the plate load of tube 502. The capacitance 566 couples resistance 514 to the grid of tube 540, bias being supplied tube 540 by battery 568 through resistances 570. It will be understood that tube 540 may be biased at less than cut-off if so desired.

The operation of my system in the situation in which it is desiredto steer the rocket by a modulated beam of light will now be described. A modulated beam of light reaching photoelectric cell develops an alternating or pulsating voltage across resistance 504 which is amplified by tube 502 which, in turn, develops an alternating voltage across the load resistance 514. This resistance 514 is coupled into the grid of tube 540 by condenser 566 in accordance with the well-known principles of resistance coupling between vacuum tubes. In-

ln this situation ductance 544 in the plate return of tube 540' prevents the passage of the audio-frequency component of plate current. Assuming switches 556 and 557 are closed, light which reaches cell 119 and which is modulated at an audio frequency corresponding to one of the resonant frequencies of the series resonant circuits hereinbefore mentioned, will energize the relay which. isresponsive to this frequency sufficiently to close its contacts. Four relays are used, as previously mentioned, each rudder control magnet being responsive; to the energization of a different relay, respectively. By modulating the light beam with any one of four audio frequencies necessary to energize the series resonant relay circuits of the-rocket, complete steering control is efiected. The beam of light may be modulated in any suitable mannerwhich is well known to those skilled in the art.

In addition to the four audio frequencies necessary to energize the series resonant relay circuits of the rocket, it is contemplated that light of two other frequencies may also be supplied. These two additional frequencies are of such a character as to cause two other of the four other relays associated with tube 54% in FIG. 21 to be operated. Relay 572 is provided to control the solenoid 4-36 of the fuze 414 which detonates the charge of explosive or the solenoid 246 which, permits the charge to be thrown from the rocket, and relays 506, 574, and 576 are provided to permit the person controlling the rocket to shift from one means of control to another while the rocket is in flight. Relays 572, 574, and 506 have windings of specific inductances, and condensers 578, 580-, and 582 have specific capacities so that each relay winding with its respective condenser constitutes a series resonant circuit.

Light of proper frequency will energize the series resonant circuit of relay 572, and if the contacts of time-delay relay 584 have been previously closed, the contacts of relay 572 upon closing energize magnet 436 through battery 586 thereby exploding the rockets charge. Time delay relay 584 constitutes a safety device. Switch 588 is closed just before or as the rocket is fired, and after a delay closes the contacts of relay 5 84, thereby assuring that the fuze shown in FIG. 20 will not prematurely operate so as to injure the personnel firing the rocket.

Particular attention is now directed to relays 574 and 576, shown in FIG. 21, wherein it is seen that the winding of relay 576 is in series with audio by-pass condenser 546, and hence, when switch 556 is opened, relay 576 will be energized by any and every audio frequency component in the plate current of tube 540 which is sufliciently strong. That is to say, relay 576 does not require a particular audio frequency to be operated, but, on the contrary, relay 576 will be energized whenever one of the other relays associated with tube 540 is energized. Relays 574 and 576 are so designed that their contacts open when the windings thereof are energized. As hereinbefore stated, relay 574 and the condenser 580 constitute a series resonant circuit, and when switch 590 is closed, this relay circuit is connected inparallel with the other series resonant circuits. Relay 574 will, therefore, be operated only when the plate current of tube 540 has a comparatively large audio frequency component corresponding to the resonant frequency of the circuitincluding the winding of this relay. It is contemplated that the searchlight apparatus should be constructed to provide the frequencies required to selectively activate the proper relays at the desired time.

The contacts of relays 574 and 57 6 are in series, and a latch 592 is provided so that once relay 574 has been energized, the contacts thereof remain open even when the relay is de-energized. As shown in FIG. 21,.this circuit containing the contacts of relays 574 and576 is in parallel with switch 454. Switch 454 is in'the grid return of tubes 444, 446, 520, and 522. As a result, when switch 454 is. open, the continued function of tubes 444, 446, 520, and 522 is dependent upon the completion 16 of thisv circuit through the; contacts of relays 5714 and- 576. Should either of. thesev contacts be. open due. to the energization of one. of; the. relays, tubes, 444, 44a, 520,. nd. 522 become incapable of guiding the rocket in response to changes in intensity of illumination which reaches photoelectric cells 108, 114, 115, and 117.

The usefulness of these. circuits is, evident when one considers. the conditions, which may be encountered. in combat. For example, assuming that the rocket started following a. beam, of light focused upon enemy aircraft, the rocket may be caused to temporarily change its direction of flight by a passing cloud, smoke, the light from exploding shells, and the interference of other searchlights; However, if the proper switch arrangement had been selected before the rocket; was, fired, a light having the proper audio frequency couldjbe projectedto bring the rocket back on the desired trajectory. The application of the light having the proper audio frequency would energize the proper relay of the group 524, 5,26 52,8, and 53.0 to turn the rocket in the desired; direction, as hereinbefore stated. At the same time, relay 576 would be energized which would result in the contacts thereof being opened, and, thus, rendering the rocket incapable of being influenced by the proportionate intensity of any light reaching cells 108, 11.4, 115, and 117, Upon return of the rocket to the original beam of light, the oper ator could remove the light having the. proper audio fre quency. The removal of the light having the proper audio frequency would de-energize relay S76. and return the rocket to the condition in which it would follow the original beam of light along the desired trajectory.

It is possible that combat conditions would become so variable due to adjacent explosions. and, other lights that the operator directing the flight of the rocket would desire to remove it completely and permanently from the influence of changes in the intensity of light. This can be readily done by modulating the source of light, with alternating current which is of the correct frequency to energize relay 574. The contacts of relay 574 will then open, and the latch 592 will hold them open, thus permanently breaking the control of photoelectric cells 108, 114, 115, and 1:17. Henceforth, the operator may steer the rocket in a positive manner by directing a modulated beam of light upon the rocket, or by radio beam methods in a manner to be described more fully hereinafter.

Various switches are provided so that any of the functions of the rocket control circuit may be chosen or eliminated. For example, when it is not desired to use the circuit which removes the rocket from the control of photoelectric cells 108, 114, 115, and 117, switch 454 is closed thereby shorting the contacts of relays 574 and 576. Relay 574 may be removed from influencing the circuit by opening switch 590, and relay 576 may be removed by closing switch 556;. When it is desired to remove the electric fuze, described hereinbefore, from the influence of a modulated beam of light or radio wave, switch 557 is opened thereby breaking the circuit of relay 572. If it is desired to render relays 524, 526, 528, and 530 non-responsive, switch 558 may be opened. Relay 506 may be rendered inoperative by opening switch 594.

The winding of relay 506 has a specific inductance and with the condenser 582 forms a series resonant circuit similar to that of the other relay circuits, hereinbefore described. This last mentioned series resonant circuit is designed to be responsive to an audio frequency component of plate current in tube 540" derived from a modulated radio frequency wave in a manner to be subsequently disclosed. Should relay 506 be energized, the contacts thereof open and the latch 596 will maintain themin the open position thereby breaking the grid circuit of tube 502 and permanently removing the rocket from the influence of a modulated light beam.

As heretofore stated, the various series resonant relay circuits are in parallel and together form a parallel resonant circuit. A change in the number of legs of this circuit by selecting any desired switching arrangement may change the series resonant frequency of every leg to some extent. Before the rocket is fired, the frequencies of the modulated light are. selected and the light source apparatus is adjusted to give the proper frequencies for the switching combination chosen in the rocket.

A switching arrangement is provided for enabling cell 110 to perform both functions of automatic sensitivity control of cells 108, 114, 115, and 117 and also control the steering of the rocket when a modulated beam is used. If it is desired that cell 110 perform both of these functions, switch 510 in the plate circuit of tube 502 is closed on its lower contact, switch 451 is opened, switch 512 is closed, switch 516 is opened, switch 560 is closed with its lower contact, and switch 562 is closed with its upper contact. Under these conditions, the plate current of tube 502 will flow through both resistances 450 and 514. Resistance 450 provides voltage drop for controlling the bias of tubes 444, 446, 520, and 522, while resistance 514 provides a load for coupling the output of the tube 502 to condenser 566 and thence to tube 540, when a beam of modulated light reaches cell 110.

As stated hereinbefore, it is intended that the rocket may be steered by changing the spectrum of the light beam, and under certain conditions this mode of operation would be desirable. As shown in FIGS. 2 and 3, the photoelectric cells 108, 110, 112, and 114 are each provided with a cover 124, 126, 128, and 130, respectively, which may be screwed into the body of the rocket and each of which is provided with a window of glass or similar material. When it is desired that the rocket follow a beam of white light these windows may be of uncolored glass or may be omitted entirely. If, however, these covers or caps 124, 126, 128, and 130 are of red, green, blue, and yellow glass, respectively, a beam of light having a spectrum from which a portion of red is removed such, for example, as that obtained by passing white light through an appropriate vapor or incandescent gas and which is directed so that the rays thereof fall upon the tail end of the rocket will reach cell 108 in proportionately less intensity than that light reaching the other cells which will receive approximately equal illumination. Thus magnet 102 is energized and the rocket is turned in the desired direction. In a similar manner, a beam of light lacking a least part of blue, green, or yellow in its spectrum will turn the rocket in other directions. It is contemplated that the covers or windows 124, 126, 128, and 1'30 will be made of the proper materials to exhibit the desired filtering qualities when used with a particular light source.

In conjunction with this description of the manner in which the rocket may be guided by changing the spectrum of the light beam, reference is again made to FIG. 21 wherein it will be observed that when switch 598 is closed, cell 110 and cell 112, which may be a photo-conductive cell, together form a means for exploding the electrically operated fuze, described hereinbefore, by the sudden changing of the spectrum of the light beam when the rocket is following a beam of white light. To accomplish this result, window or cover 128 will be of plain or uncolored glass, and window or cover 126 will be of colored glass such, for example, as red and will act as a filter. Conductors '600 and 602, shown in FIGS. 21 and 22, lead from cells 110 and 112 to the vacuum tube 604 which has a relay 606 in the plate circuit thereof. The battery =608 supplies a grid bias for this tube 604 and battery 610 supplies the plate potential therefor. Assuming that switch 612 is closed, the grid circuit of tube 604 is traced as follows: from the grid of tube 604 through resistance 505, through resistance 504, through battery 608, and to the filament of tube 604. Battery 608 has such a potential that no grid current flows at any time in tube 604. The battery 524 supplies potential to cells 110 and 112, and the current flowing through cell 110 18 passes through resistance 504 and causes a voltage drop across this resistance. If switch 598 is closed, the current flowing through cell 112 passes through resistance 505. The voltage drop across 504 tends to make the grid of tube 604 negative with respect to the filament thereof,

while the voltage drop across 505 tends to make this grid positive.

The operation of the rocket under these conditions in which the spectrum of the light beam is changed in order to elfect the steering of the rocket will now be described. The bias of battery 608 limits the plate curren to just below the amount necessary to operate the plate relay 606. If white light is directed upon the covers, resistances 504 and 505 are adjusted until the voltage drops across them are approximately equal. If a light lacking red is now suddenly applied to the rocket, these voltages become unequal because the light reaching cell is decreased. As a result of this unequality of voltages, the negative bias of tube 604 is reduced, and relay 606 is energized thereby closing the contacts thereof to operate magnet 436.

A sound operated circuit is also provided in the rocket of the instant invention and is disclosed in FIG. 22. The function of this sound operated circuit is to explode the rocket as it arrives at a position abreast of an enemy aircraft. So long as the rocket is approaching the target, the sound from the aircraft will reach microphone 28 in greater intensity than that which reaches microphone 30. At the moment the rocket approaches the level or altitude of the aircraft or rises above it by even a small amount or at a small angle, the sound will reach the microphone 30 in equal or greater intensity than that reaching microphone 28. When switches 614 and 616, shown in FIG. 22, are closed, the contacts of relay 618 are in parallel connection with those of relay 572, shown in FIG. 21. When these contacts are closed the electric fuze of FIG. 20 is operated to thereby explode the main charge. The circuit of FIG. 22 is designed to energize relay 618 at the moment the sound reaching microphone 30 exceeds that reaching microphone 28.

Microphones 28 and 30 may be identical except for the direction of maximum response and are coupled by identical transformers 624 and 626, respectively, to the control grids of identical tubes 628 and 630. Battery 632 supplies a bias to both tubes628 and 630. Battery 634 supplies the screen grid potential when switch 636 is closed. The .bias of battery 632 is such that it permits tubes 628 and 630 to act as reactifiers and may be cut off entirely or nearly cut off. In the plate circuit of each tubes 628 and 630 to act as rectifiers and may be cut tube 628 being shown in FIG. 22 as comprising choke 638 and condensers 640 and 642. The audio filter for tube 630 comprises choke 644 and condensers 646 and 648. These audio frequency filters may be of identical values. Plate potential is supplied both tubes 628 and 630 by battery 633. Resistance 650 is in the plate return of tube 628, and resistance 652 is in the plate return of tube 630, and these resistances may be of equal value. If tubes 628 and 630 are biased to cut oif and the audio frequency filters are sutficiently large, as is desired, an almost steady direct current potential will exist across resistance 650 when a sound reaches microphone 28, and the voltage drop across resistance 650 will be directly proportional to the volume of sound reaching microphone 28. Similarly, the voltage drop across resistance 652 is proportional to the intensity of sound reaching microphone 30. The voltage drop across resistanoe 650 is such as to introduce into the grid circuit of tube 654 a potential tending to make the grid negative with respect to the filament thereof. The voltage drop across resistance 652 tends to make the grid positive with respect to the filament of tube 654. If these voltage drops are equal, it will be apparent thatno effective voltage is introduced into the grid circuit of tube 654.

Turning now to a discussion of the operation of this sound operated circuit, battery 656 which biases tube 654 is so chosen that with a given value of plate battery 658, battery 656 alone will be suflicient to bias tube 654 so that the plate current is just insufficient to energize relay 618 and close the contacts thereof. As the rocket ascends toward the target, the sound will reach microphone 28 in ever increasing intensity which causes the voltage drop across resistance 650 to become greater thereby biasing tube 654 more and more heavily. At the moment that the rocket comes abreast of the target, sound will reach microphone 30 in greater intensity than that reaching microphone 28, and the positive voltage drop across resistance 652 will exceed the negative voltage drop across resistance 650. The plate current of tube 654 will then increase to a value sufiicient to energize relay 618 thereby closing the contacts thereof to energize solenoid 436 and explode the charge of the rocket.

The sound emanating from the rocket itself may be provided for by biasing tubes 628 and 630 so heavily by battery 632 that no plate current flows until some other sound is added at the microphones. Also, it will be observed that since the rocket sound may be expected to reach microphones 28 and 30 in substantially the same intensity, the voltage drops, if any, across resistances 650 and 652 due to this sound source will be approximately equal and opposite.

It will be understood that resistances 650 and 652 may be made variable to allow adjustment, and a switch such, for example, as that designated by numeral 660 may be provided to open the microphone circuits when desired.

A timedelay relay is shown at 662 and is provided with battery 664 for energizing the winding thereof. Switch 666 is included for opening and closing the circuit. When switch 666 is closed, the relay 662 has the con tacts thereof in parallel connection with those of relay 572. When the contacts of relay 662 are closed the fuze of FIG. 20 will be operated. The period of time delay of relay 662 may be chosen either to explode the charge at a moment when it is calculated that the rocket will pass close to the target, or the period of time delay may be so chosen as to explode the rocket at the end of the rockets flight or substantially at the end thereof so that the rocket will be destroyed and the fragments thereof will fall to the earth.

FIG. 22 also discloses the circuitry of the radio frequency equipment used for steering the rocket and exploding the fuze by radio waves. The antenna 32 is mounted on the outside of the rocket casing as shown in FIG. 1. Transformer 668 couples antenna 32 to tube 670 with condenser 672 for proper tuning, and battery 674 is provided to supply a bias to tube 670. When biased, tube 670 acts as a detector or rectifier and the plate circuit thereof contains the radio frequency filter comprising choke 676 which surpresses radio frequency components of plate current. Condensers 678 and 680 are also provided in the plate circuit of tube 670. Battery 682 supplies plate potential for tube 670, and the audio frequency choke 67 6 supplies the load across which the audio frequency voltage is developed. Choke 676 has a high impedance at the lowest audio frequency to be used. When switch 684 is closed, wire 686 connects the filament of tube 670 to the filament of tube 540, and wire 688, when switches 563 and/or 562 are properly closed also, connects one side of the choke 676 to one side of coupling condenser 566. Therefore, the recti fied output of tube 670 is passed on to tube 540 and may operate any of the relays in the plate circuit of tube 540 when the radio wave reaching antenna 32 is modulated at the proper audio frequency.

FIG. 23 shows the radio frequency transmitting circuit for supplying the modulated radio wave which will properly operate the radio controlled circuit of FIGS. 21 and 22. The antenna and ground are shown at 690 and 692, respectively, the antenna coupling coil at 694 and the primary inductance at 696. The circuit of tube 698 is a simple Hartley oscillator circuit having'gridleak bias and a transformer in the filament return for introducing the modulating frequency. The condenser 700 by-passes radio frequency. Audio frequency generators of any desirable type such, for example, as vacuum tube oscillators employing transformer feedback are shown at 702, 704, 706, 708, 710, 712, and 714. The output sides of these audio frequency generators may be connected to the primary 716 of the transformer 718 in the filament return of the radio frequency generator tube 698 through variable resistance 720 by closing the appropriate switch of the group 722, 724, 726, 728, 730, 732 and 734. The frequencies of the audio generators are selected so as to be appropriate to operate the relays of FIG. 21, 506, 524', 526, 528-, 530, 572, and 574 each of which is responsive to a different frequency. The audio generators may be so chosen as to assure the supply of the necessary audio frequencies to operate the switching arrangement of FIG. 21, or the generators may contain means for varying their frequencies within necessary limits such, for example, as tapped transformers.

The switching arrangement of FIG. 21 permits tube 540 to be excited at the same time by the output of tubes 502 and 670 so that the operator controlling the flight of the rocket may alternately use the modulated light beam and radio wave methods of steering the rocket if conditions make this desirable. To permit this, switch 563, FIG. 21, is closed, switch 562 is closed with its upper contact, and either switch 564 or switch 560 is closed depending upon other considerations such, for example, as whether it is desired to have tube 502 perform its other function, mentioned hereinbefore, of sensitivity control. This switching arrangement connects both the output of tube 502 and the output of tube 670 to the condenser 566. The tube plate circuits are in parallel, one leg consisting of battery 518 and resistance 514 in series, and the other leg consisting of battery 682 and choke 676 in series. Batteries 518 and 682 should be of the same potential.

The circuit diagram which is schematically shown in FIG. 24 is a modification of a portion of the circuit of FIG. 21 and will enable the rocket to follow a modulated beam of light during daylight hours, the sunlight having no effect thereupon. The photoelectric cells 108 and 114 develop an alternating voltage across resistances 440 and 442, respectively, at the frequency of modulation of the directing light beam. The alternating currents thus produced in the plate circuits of tubes 444 and 446 are transferred by transformers 744 and 746 to the grids of tubes 468 and 472. Any sunlight which reaches cells 108 and 114 will serve to alter the steady biases of tubes 444 and 446 in identical degrees and will not influence the relative alternating current outputs of these tubes, providing their characteristics are linear. Tubes 444 and 446 will be so chosen and biased so as to accomplish this result. The differential relays 740 and 742 have contacts which are connected similarly as those of relays 476 and 480 in FIG. 21 or those of relays 186 and 188 in FIG. 6. When the plate current of tube 468 exceeds that of tube 472, relay 740 is energized, and, conversely, when the plate current of tube 472 exceeds that of tube 468, relay 742 is energized. Similarly as hereinbefore described, relays 740 and 742 control the energization of magnets and 102. It is intended that a duplicate circuit of that disclosed in FIG. 24 and which includes cells 115 and 117 be provided to control a pair of relays similar to relays 740 and 742 and which in turn will control the energization of magnets 104 and 105. If desired, the outputs of tubes 468 and 472 may be filtered before applying them to the differential relays. Transformers 744 and 746 may be resonant at the frequency of modulation of the coutrolled light beam to provide maximum response.

It is to be understood that any or all of the forms of the rocket herein disclosed may be controlled by either a beam of unmodulated light, a beam of spectrum controlled 21 light, a beam of modulated light, or a radio beam, or any combination of these control means.

Although the photoelectric cells hereinbefore mentioned have been referred to as being of the photo-conductive type, they may be replaced by photo-emissive or photovoltaic devices in equivalentcircuits. Similarly, the vacu um tubes, hereinbefore described and shown in the accompanying drawings, may be replaced by other electron tubes having equivalent functions. It will be understood that amplifiers may be added where desired in order to increase the range of the rocket. Likewise, dry fuels of a suitable type may be utilized instead of the liquid fuels herein disclosed. It is obvious that simple devices of electrical or mechanical nature such, for example, as levers may be utilized to provide a mechanical advantage for the action of the magnets hereinbefore disclosed.

While the invention has been described with reference to certain preferred examples thereof which give satisfactory results, it will be understood by those skilled in the art to which the invention pertains, after understanding the invention, that various changes and modifications may be made without departing from the spirit and scope of the invention, and it is my intention, therefore, to cover in the appended claims all such changes and modifications.

The invention herein described and claimed may be manufactured and used by or for the Government of the United States of America for governmental purposes without payment of any royalties thereon or therefor.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

l. A rocket including a frame, means forming a combustion chamber, a nozzle forming an exhaust vent for said chamber, means pivotally mounting said first mentioned means and nozzle upon said frame, a plurality of light sensitive devices mounted in said frame, and means associated with said nozzle and said light sensitive devices and controlled by the latter for changing the direction in which said nozzle points, said last named means including magnetic attraction members fixed to said nozzle, a plurality of electromagnets disposed at substantially equally spaced intervals around the periphery of said frame and adapted when energized to exert attracting forces on adjacent attraction members thereby to move said nozzle to new positions with respect to said frame respectively, a source of potential for energizing said electromagnets, and apparatus controlled from said light-sensitive devices for connecting said source of potential selectively to said electromagnets when the light intensities at said light-sensitive devices vary relatively to one another in predetermined amounts.

2. In apparatus of the character disclosed, the combina tion of a rocket body having a chamber therein, an explosive charge carried within said chamber and adapted to be forcibly ejected therefrom, an initially compressed spring mounted in said chamber for ejecting said charge, a latch mechanism associated with said spring and adapted to normally maintain said spring in compressed position and maintain said charge within said chamber, light-sensitive means mounted on said body, a solenoid operatively asso ciated with said latch mechanism and adapted when energized to operate said latch mechanism and thereby release said spring and charge, and circuit means including a source of electrical power interconnecting said light-sensitive means and said solenoid whereby said solenoid is energized and said charge is ejected when the light reaching said light-sensitive means is varied in a predetermined manner.

3. A rocket including a frame, means forming a combustion chamber, a nozzle secured to said chamber and forming an exhaust vent therefor, means for pivotally mounting said first named means on the frame with the nozzle normally arranged in alignment with the axis of the rocket, a plurality of electroresponsive devices mounted at spaced intervals upon said frame and adapted when energized to change the direction of said nozzle with respect to said axis selectively in accordance with the energization of said devices, means for returning said nozzle to its original aligned position when said devices are de-energized, a plurality of pairs of light-sensitive devices mounted on said frame in predetermined spaced positions with respect to said electroresponsive devices, and means interconnected to the electroresponsive devices and to said light-sensitive devices and controlled by the latter for energizing the electroresponsive devices and thereby changing the position of said nozzle with respect to said axis in response to changes in the relative intensities of light reaching said pairs of said light-sensitive devices.

4. A rocket including a frame, means forming a combustion chamber, a nozzle secured to said chamber and forming an exhaust vent therefor, means pivotally mounting said first named means and nozzle upon said frame with the nozzle normally arranged in alignment with the axis of the rocket, a plurality of electroresponsive devices mounted at spaced intervals upon said frame and adapted when energized to change the position of said nozzle with respect to said axis selectively in accordance with the energization of said devices, means for returning said nozzle to its original aligned position when said devices are de-energized, a plurality of light-sensitive devices mounted at spaced intervals in said frame around the periphery thereof in predetermined positions with respect to said electroresponsive devices, a plurality of amplifiers energized from said light-sensitive devices, and a plurality of relay means connected in the output circuits of said amplifiers and controlled by said light-sensitive devices, said plurality of relay means being operatively connected to and controlling the energization of said plurality of electroresponsive devices whereby the position of said nozzle is controlled by the relative intensities of light reaching said light-sensitive devices.

5. A rocket including a frame, means forming a combustion chamber, a nozzle secured to said chamber and forming an exhaust vent therefor, means pivotally mounting said first mentioned means and nozzle upon said frame with the nozzle normally arranged in alignment with the axis of the rocket, four electroresponsive devices mounted at substantially equally spaced peripheral intervals upon said frame and adapted when energized to change the position of said nozzle with respect to said axis selectively in accordance with, the energization of said devices, means for returning said nozzle to its original aligned position when said devices are de-energized, four light-sensitive devices mounted atsubstantially equally spaced intervals in said frame around the periphery thereof in predetermined positions with respect to said electro-. responsive devices, a pair of dual amplifier channels, each of said amplifier channels having a pair of relays in the output circuit thereof, said amplifier channels having their inputs connected respectively to pairs of oppositely disposed light-sensitive devices, said relays being adapted to be energized selectively in accordance with which light-sensitive device of the pair has the greater intensity of illumination applied thereto, said relays being operatively connected to and controlling the energization of said electroresponsive devices whereby the position of said nozzle is controlled by the relative intensities of light reaching pairs of said light-sensitive devices.

6. A rocket according to claim 5 including, in addition, four filter devices respectively associated with said light-sensitive devices for absorbing all rays of light except those within predetermined spectrum bands whereby light reaching each of the light-sensitive devices has a predetermined different spectrum.

7. A rocket adapted to follow a beam of light and including a frame, means forming a combustion chamber, a nozzle secured to said chamber and forming an exhaust vent therefor, means pivotally mounting said first named means and nozzle upon said frame with the nozzle normally arranged in alignment with the axis of the rocket, 

